Interstitial fluid is a major component of the liquid
environment in the body and fills the spaces between the body’s
cells. In contrast, blood circulates only within the circulatory
vessels of the body and is composed of blood cells and the liquid
part of the blood, plasma. Both fluids contain special components
called biomarkers, which are valuable indicators of bodily health.
These biomarkers include various types of molecules such as
proteins, hormones or DNA, and can also include drugs and
metabolites.
